The article presents the results of studying the effect of biologically active extracts from seaweed (Ahnfeltia tobuchiensis and Saccharina japonica) on the development of tomato seedlings in drought conditions. The analysis of extracts obtained from seaweed was performed at solution pH values ranging from 5.5 to 7.5. Extracts from Ahnfeltia tobuchiensis are characterized by a high content of nitrogen, easily hydrolyzable carbohydrates, and polyphenols; extracts from Saccharina japonica have a maximum concentration of iodine. Tomato seedlings (Solanum licopersicum) were used to study the effectiveness of seaweed extracts. The experiment included 8 options: options 1 to 6 – spraying plants with extracts from the corresponding seaweed under stress (drought); option 7 (control) – spraying plants with water under stress; option 8 – stress-free control. It is proved that seaweed extracts increase the rate of plant growth during the drought period and their recovery after the drought. It has also been proven that extracts help support plants during periods of drought, restore and increase green biomass to levels similar to those in plants without dehydration stress. The growing in biomass is associated with an increase in the relative water content in tomato leaves; accumulation of minerals, nitrogenous substances, iodine, and easily hydrolyzable carbohydrates. Treatment with aqueous extracts of Ahnfeltia tobuchiensis and alkaline extracts of Saccharina japonica is most effective for the growth and stability of tomato seedlings during drought and their recovery after drought.

Kadnikova Irina A., Aminina Natalya M.

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